In finance, what is a return on an investment?
Choose an answer, then check it.
Finance · Foundations
Return
On this page 9 sections
In 30 seconds
A Return The gain or loss on an investment over a period of time, usually expressed as a percentage of the starting value. Full entry → is the gain or loss on an investment over a period of time, usually stated as a percentage. The simple formula: return = (ending value − starting value) ÷ starting value; $500 growing to $550 is a 10% return. Returns come from Income Payments an investment makes while it is held, such as dividends on a stock or interest on a bond. Full entry → (dividends and interest) and from price change (capital gains and losses). Expected returns are forecasts; realized returns are records. Higher expected returns carry higher risk, and past returns are history, not promises.
Why this matters
Every investment promises to give something back, and return is the yardstick for how much. Without it, you cannot tell a good investment from a weak one, compare a $500 stake with a $50,000 stake, or judge whether the risk someone asked you to accept was worth taking. Learning the one formula, the two building blocks, and the difference between expectation and reality turns vague hopes about growing money into a number you can check — and lets you see through pitches that treat past results as guarantees.
The college version
What return is
A return is the gain or loss on an investment over a period of time. CFI, the Corporate Finance Institute, defines a rate of return as the gain or loss of an investment over a certain period, typically expressed as a percentage. Investopedia states the same idea in plainer words: a return is the money made or lost on an investment over some period of time. OpenStax's Principles of Finance describes return as the benefit, or profit, the investor expects from an expenditure. Three sources, one core idea: return measures what an investment gives back compared with what went in. The measurement runs both ways: a positive return is a gain and a negative return is a loss — an investment that loses value does not return zero, it returns a negative number.
The simple return formula
The formula this lesson teaches has one step: return = (ending value − starting value) ÷ starting value. Worked example: an investment of $500 that is worth $550 after one year. First subtract: $550 − $500 = $50. Then divide by the starting value: $50 ÷ $500 = 0.10. Move the decimal two places and the return is 10%. The same arithmetic runs in reverse: if the investment had ended the year at $450, then $450 − $500 = −$50 and −$50 ÷ $500 = −0.10, a 10% loss. OpenStax demonstrates the same holding-period calculation (a stock bought at $228.50 and sold at $261.90 earns 14.62%), and CFI's standard formula adds any income received during the holding period into the numerator. The simple version here tracks price change; the next section adds income.
Income and capital gains
Finance splits a return into two building blocks. Income is what the investment pays you while you hold it — dividends on a stock, interest on a bond. Original example: a $3,000 certificate of deposit pays $90 in interest over a year; that $90 is income. Capital gain The profit from an investment whose price rises above what was paid for it. Full entry → is the change in the investment's own price — buying low and selling high. Original example: 25 shares of a bakery company bought at $8 each cost $200; sold at $10 each they bring $250; the $50 difference is a capital gain. If the price had fallen to $6 each, the $50 difference would be a Capital loss The loss from an investment whose price falls below what was paid for it. Full entry →. OpenStax puts the two together: total dollar return equals dividend income plus capital gain. A price that never moves can still produce a positive return through income, and a price rise with no payments is pure capital gain.
Expected versus realized
Expected return The return an investor anticipates before the outcome is known; a forecast, not a promise. Full entry → is what you anticipate before the outcome is known. CFI defines it as the expected value of the distribution of possible returns — a weighted guess across the outcomes that could happen — and notes that it is based on historical data, which may or may not reliably forecast the future. Realized return The return that actually occurred over a specific period, measured after the fact. Full entry → is what actually happened. OpenStax defines it as the Total return The return that combines income received with the change in price. Full entry → that occurs over a particular time period, measured after the fact. Original example: at the start of the year an analyst expects a fund to return 8%; at year-end the fund returned 3%. The 8% was the expected return, a forecast; the 3% is the realized return, a record. The gap is normal, not a failure.
Return and risk
Return and risk are studied as a pair, and the pairing has a general shape: higher expected returns come with higher risk. The SEC's Investor.gov site, puts it directly — as investment risks rise, investors seek higher returns to compensate themselves for taking such risks. Investopedia agrees: investors require a higher expected return for riskier investments to compensate for the additional risk of loss. Original example: a savings account offers a small, near-certain return; a young technology company's stock offers a larger expected return because its results swing far wider. The extra expected return is the compensation for the extra uncertainty. Risk is a sibling topic with a lesson of its own; here it appears only as return's partner in the trade.
Comparing returns
Two comparisons matter, and both need a common basis. Across investments, returns are compared in percentages, not dollars. OpenStax explains why: the percent return tells the investor how much is received for each dollar invested, so investments of different sizes can be compared. Original example: a $100 gain on a $500 investment and a $50 gain on a $250 investment are both 20% returns — the same performance per dollar, different dollar amounts. Across time, a return earned over three months cannot be compared with one earned over two years; finance restates returns on a yearly, or annualized, basis. OpenStax annualizes a three-month holding-period return into an effective annual rate so it can be weighed against other opportunities, and CFI's annualized rate of return does the same. The general practice: put every return on the same measuring stick — per dollar invested and per year.
The honest framing
Past returns are history, not promises. CFI warns that expected return is based on historical data, which may or may not provide reliable forecasting of future returns — the outcome is not guaranteed. Investor.gov opens its risk page with the same reality check: all investments involve some degree of risk. Original example: a fund that returned 18% last year can return −4% next year; last year's number is a record of what happened, not a contract for what will. Any pitch that treats a past return as a promise is misreading the measurement. Returns are measured backward and hoped forward.
Eli explains
The same idea, in plain words
Explain it like I’m 10
Return is the measuring tape of investing. It tells you what an investment gave back compared with what went in — not in dollars alone, but as a percentage, so a $50 gain on $500 and a $5 gain on $50 both read as the same 10% return. The tape measures two things at once: the payments you collected while holding the investment, and the change in what the investment itself is worth. There are two numbers in every investment story: the one you hoped for before it started, the expected return, and the one that actually happened, the realized return. They rarely match. And the tape never lies about the past but says nothing about the future: last year's measurement is history, not a promise.
Picture it like this
Think of a lemonade stand season. You put $40 into lemons, sugar, and cups. At the end of the summer you count every dollar the stand earned and add what your leftover setup is worth. If you finish with $48, your return is ($48 − $40) ÷ $40 = 20% — for every dollar you put in, you got $1.20 back. The return combines what the stand paid out to you along the way with the change in what your setup is worth at the end.
Where the picture stops working
Where the analogy breaks down:a lemonade stand's season ends and the counting is simple, but an investment's value keeps moving while you hold it, and the price on any given day is a market guess, not a fixed number. The stand's recipe is your own; an investment's future depends on thousands of strangers' decisions. And one good summer proves nothing about next summer.
Worked example
Ava puts $500 into a one-year share of a local bike-repair cooperative. After a year, her share is worth $550, and she received no payments along the way. Starting value: $500. Ending value: $550. Return = (ending value − starting value) ÷ starting value = ($550 − $500) ÷ $500 = $50 ÷ $500 = 0.10 = 10%. For every dollar she invested, she came away with $1.10 worth. If the share had instead ended the year at $450, the same formula gives ($450 − $500) ÷ $500 = −$50 ÷ $500 = −0.10, a 10% loss. Same one-step formula, either direction.
Key takeaway
A return is the gain or loss on an investment over a period, measured as (ending value − starting value) ÷ starting value. Income and price change both count, and past returns are history — not promises.
Quick check
3 questions here, of 5 in this lesson’s practice set. Answers stay hidden until you check.
Priya bought a share for $200 and sold it one year later for $230. Using the simple return formula, what was her return?
Choose an answer, then check it.
Leila's investment paid $60 in interest during the year, and its price rose from $1,000 to $1,040. Which part of her return is the capital gain?
Choose an answer, then check it.
Study tools & related lessonsYou’ll learn to · Common mistakes · Easily confused · Key vocabulary · Related
You’ll learn to
- Define return as the gain or loss on an investment over a period of time, using the working definitions from CFI, OpenStax, and Investopedia.
- Compute a simple return with the formula (ending value − starting value) ÷ starting value, showing the arithmetic.
- Distinguish income from capital gain, each with an original example, and name capital loss.
- Contrast expected return with realized return.
- Explain the general pairing of return and risk, and the honest framing that past returns are history, not promises.
Common mistakes
Treating return as always a gain
A return can be negative. An investment that lost value produced a negative return, which is still a return.
Forgetting that income counts
A price that never moves can still produce a return through dividends or interest; total return combines income with price change.
Confusing expected with realized
The expected return is the forecast made in advance; the realized return is the record of what actually happened. They often differ.
Comparing returns on different time frames
A 10% return over one month and a 10% return over three years are not the same achievement; returns must be put on a common yearly basis to compare fairly.
Reading the past as a promise
Past returns are history; expected returns are based on historical data and are not guaranteed, and every investment carries some risk.
Easily confused
Income vs. capital gain
Income is what the investment pays you while you hold it, like interest or dividends; a capital gain is the rise in the investment's own price. Both count toward total return, and a fall in price is a capital loss.
Expected return vs. realized return
Expected return is what you anticipate before the outcome, a forecast built from possible outcomes; realized return is what actually occurred over the period, measured after the fact.
Key vocabulary
- Return
- The gain or loss on an investment over a period of time, usually expressed as a percentage of the starting value.
- Simple return
- The percentage change in an investment's value, calculated as (ending value − starting value) ÷ starting value.
- Income
- Payments an investment makes while it is held, such as dividends on a stock or interest on a bond.
- Capital gain
- The profit from an investment whose price rises above what was paid for it.
- Capital loss
- The loss from an investment whose price falls below what was paid for it.
- Expected return
- The return an investor anticipates before the outcome is known; a forecast, not a promise.
- Realized return
- The return that actually occurred over a specific period, measured after the fact.
- Annualized return
- A return restated as a yearly figure so investments held for different lengths of time can be compared.
- Total return
- The return that combines income received with the change in price.
Sources & references
- Principles of Finance, Section 15.1: Risk and Return to an Individual Asset — OpenStax, Rice University
- Rate of Return (Corporate Finance Institute) — Corporate Finance Institute (CFI)
- Expected Return (Corporate Finance Institute) — Corporate Finance Institute (CFI)
- Return: What It Means in Investing, How It Is Measured — Investopedia
- What is Risk? (Investor.gov, Investing Basics) — U.S. Securities and Exchange Commission, Investor.gov
EliExplains lessons are original prose written from the open, credible references above. See Copyright & Licensing.
Researched 2026-08-21
Educational content only. It is not medical, legal or professional advice. Found an error? Tell us.